• Title/Summary/Keyword: Field validation

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Deformable image registration in radiation therapy

  • Oh, Seungjong;Kim, Siyong
    • Radiation Oncology Journal
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    • v.35 no.2
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    • pp.101-111
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    • 2017
  • The number of imaging data sets has significantly increased during radiation treatment after introducing a diverse range of advanced techniques into the field of radiation oncology. As a consequence, there have been many studies proposing meaningful applications of imaging data set use. These applications commonly require a method to align the data sets at a reference. Deformable image registration (DIR) is a process which satisfies this requirement by locally registering image data sets into a reference image set. DIR identifies the spatial correspondence in order to minimize the differences between two or among multiple sets of images. This article describes clinical applications, validation, and algorithms of DIR techniques. Applications of DIR in radiation treatment include dose accumulation, mathematical modeling, automatic segmentation, and functional imaging. Validation methods discussed are based on anatomical landmarks, physical phantoms, digital phantoms, and per application purpose. DIR algorithms are also briefly reviewed with respect to two algorithmic components: similarity index and deformation models.

Force identification by using specific forms of PVDF patches

  • Chesne, Simon;Pezerat, Charles
    • Smart Structures and Systems
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    • v.15 no.5
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    • pp.1203-1214
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    • 2015
  • This paper deals with the experimental validation of the use of PVDF Patches for the assessment of spatial derivatives of displacement field. It focuses more exactly on the shear Force Identification by using Specific forms of PVDF patcHes (FISH) on beams. An overview of the theoretical approach is exposed. The principle is based on the use of the weak form of the equation of motion of the beam which allows the shear forces to be extracted at one edge of the sensor when this last has a specific form. The experimental validation is carried out with a cantilever steel beam, excited by a shaker at its free boundary. The validation consists in comparing the shear force measured by the designed sensor glued at the free edge and the directly measured force applied by the shaker. The sensor is made of two patches, called the "stiffness" patch and the "mass" patch. The use of both patches allows one to identify correctly the shear force on a large frequency domain. The use of only the stiffness patch is valid in the low frequency domain and has the advantage to have a frequency-independent gain that allows its use in real time.

Domestic air demand forecast using cross-validation (교차검증을 이용한 국내선 항공수요예측)

  • Lim, Jae-Hwan;Kim, Young-Rok;Choi, Yun-Chul;Kim, Kwang-Il
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.27 no.1
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    • pp.43-50
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    • 2019
  • The aviation demand forecast field has been actively studied along with the recent growth of the aviation market. In this study, the demand for domestic passenger demand and freight demand was estimated through cross-validation method. As a result, passenger demand is influenced by private consumption growth rate, oil price, and exchange rate. Freight demand is affected by GDP per capita, private consumption growth rate, and oil price. In particular, passenger demand is characterized by temporary external shocks, and freight demand is more affected by economic variables than temporary shocks.

Computer-aided approach of parameters influencing concrete service life and field validation

  • Papadakis, V.G.;Efstathiou, M.P.;Apostolopoulos, C.A.
    • Computers and Concrete
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    • v.4 no.1
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    • pp.1-18
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    • 2007
  • Over the past decades, an enormous amount of effort has been expended in laboratory and field studies on concrete durability estimation. The results of this research are still either widely scattered in the journal literature or mentioned briefly in the standard textbooks. Moreover, the theoretical approaches of deterioration mechanisms with a predictive character are limited to some complicated mathematical models not widespread in practice. A significant step forward could be the development of appropriate software for computer-based estimation of concrete service life, including reliable mathematical models and adequate experimental data. In the present work, the basis for the development of a computer estimation of the concrete service life is presented. After the definition of concrete mix design and structure characteristics, as well as the consideration regarding the environmental conditions where the structure will be found, the concrete service life can be reliably predicted using fundamental mathematical models that simulate the deterioration mechanisms. The prediction is focused on the basic deterioration phenomena of reinforced concrete, such as carbonation and chloride penetration, that initiate the reinforcing bars corrosion. Aspects on concrete strength and the production cost are also considered. Field observations and data collection from existing structures are compared with predictions of service life using the above model. A first attempt to develop a database of service lives of different types of reinforced concrete structure exposed to varying environments is finally included.

Numerical simulation of advection-diffusion on flow in waste stabilization ponds (1-dimension) with finite difference method forward time central space scheme

  • Putri, Gitta Agnes;Sunarsih, Sunarsih;Hariyanto, Susilo
    • Environmental Engineering Research
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    • v.23 no.4
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    • pp.442-448
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    • 2018
  • This paper presents the numerical simulation of advection-diffusion mechanism of BOD concentration which was used as an indicator of waste only in one flow-direction of waste stabilization ponds (1-dimension (1-D)). This model was represented in partial differential equation order 2. The purpose of this paper was to determine the simulation of the model 1-D of wastewater transport phenomena based advection-diffusion mechanism and did validate the model. Numerical methods which was used for the solution of this model is finite difference method with Forward Time Central Space scheme. The simulation results which was obtained would be compared with field observation data as a validation model. Collection of field data was carried out in the Wastewater Treatment Plant Sewon, Bantul, D.I. Yogyakarta. The results of numerical simulations were indicate that the advection-diffusion mechanism takes place continuously over time. Then validation of the model was state that there was a difference between the calculation results with the field data, with a correlation value of 0.998.

Development and Validation of Distributed Cognition Theory Based Instructional Strategy in Science Class Using Technology (테크놀로지 활용 과학 수업에서 분산인지 이론 기반 수업 전략의 개발 및 타당화)

  • Ja-Heon Noh;Jun-Ho Son;Jong-Hee Kim
    • Journal of the Korean Society of Earth Science Education
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    • v.17 no.1
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    • pp.1-19
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    • 2024
  • This study is a design and development study that developed instructional strategies based on distributed cognitive theory for science classes using technology according to procedures that ensured reliability and validity. To develop instructional strategies, development study and validation study were conducted according to design and development research methodology procedures. In the development study, an initial instructional strategy was developed through prior literature review and prior expert review. In the validation study, the instructional strategy was validated using internal validation (expert validation, usability evaluation) and external validation (field application evaluation) methods, and the final instructional strategy was developed. The final instructional strategy consisted of 3 instructional principles, 9 instructional strategies, and 38 detailed guidelines. Through this study, the researcher suggested the suitability of instructional strategies for science classes using technology, the usefulness of blocks and teaching and learning processes, the possibility of using technology as a cognitive tool, the need for teachers' efforts to cultivate teaching capabilities using technology, and the needs lesson plan that takes into account conditions affecting the application of instructional strategies.

The Fundamental Requirements in the Application of Relaxed Eddy Accumulation Method for Measuring the Trace Gas Fluxes

  • Kim Ki-Hyun
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.E1
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    • pp.37-39
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    • 2005
  • It is well perceived that micrometeorological approach is one of the most reliable method for the quantification of vertical fluxes of trace components in the atmosphere. In this study, the feasibility of relaxed eddy accumulation (REA) method is discussed with respect to its reliability in the field application. Knowing that the use of micrometeorological approaches requires validation of analytical uncertainties involved, the problems and issues associated with its application are discussed to stimulate the proper employment of such technique in the field study.

A Practical Power System Stabilizer Tuning Method and its Verification in Field Test

  • Shin, Jeong-Hoon;Nam, Su-Chul;Lee, Jae-Gul;Baek, Seung-Mook;Choy, Young-Do;Kim, Tae-Kyun
    • Journal of Electrical Engineering and Technology
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    • v.5 no.3
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    • pp.400-406
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    • 2010
  • This paper deals with parameter tuning of the Power System Stabilizer (PSS) for 612 MVA thermal power plants in the KEPCO system and its validation in a field test. In this paper, the selection of parameters, such as lead-lag time constants for phase compensation and system gain, is optimized using linear and eigenvalue analyses. This is then verified through the time-domain transient stability analysis. In the next step, the performance of PSS is finally verified by the generator's on-line field test. After the field test, measured and simulated data are also compared to prove the effectiveness of the models used in the simulations.

Regionalization of CN values at Imha Watershed with SCE-UA (최적화 기법을 이용한 임하호유역 대표 CN값 추정)

  • Jeon, Ji-Hong;Kim, Tae-Dong;Choi, Dong-Hyuk
    • Journal of The Korean Society of Agricultural Engineers
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    • v.53 no.5
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    • pp.9-16
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    • 2011
  • Curve Numbers (CN) for the combination of land use and hydrologic soil group were regionalized at Imha Watershed using Long-term Hydrologic Impact Assessment (L-THIA) coupled with SCE-UA. The L-THIA was calibrated during 1991-2000 and validated during 2001-2007 using monthly observed direct runoff data. The Nash-Sutcliffe (NS) coefficients for calibration and validation were 0.91 and 0.93, respectively, and showed high model efficiency. Based on the criteria of model calibration, both calibration and validation represented 'very good' fit with observe data. The spatial distribution of direct surface runoff by L-THIA represented runoff from Thiessen pologen at Subi and Sukbo rain gage station much higher than other area due to the combination of poor hydrologic condition (hydrologic soil C and D group) and locality heavy rainfall. As a results of hydrologic condition and treatment for land use type based on calibrated CNs, forest is recommended to be hydrologically modelled dived into deciduous, coniferous, and mixed forest due to the hydrological difference. The CNs for forest and upland showed the poor hydrologic condition. The steep slope of forest and alpine agricultural field make high runoff rate which is the poor hydrologic condition because CN method can not consider field slope. L-THIA linded with SCE-UA could generated a regionalized CNs for land use type with minimized time and effort, and maximized model's accuracy.